CRACmediated

CRACmediated refers to a cellular signaling pathway involving the Calcium Release-Activated Calcium (CRAC) channels, which play a crucial role in calcium influx in non-excitable cells. These channels are primarily composed of the ORAI family proteins, notably ORAI1, and are activated following the depletion of calcium stores in the endoplasmic reticulum (ER). The process is essential for various physiological functions, including immune response, gene expression, and cell proliferation.

The mechanism of CRAC-mediated calcium entry begins with the activation of receptor-operated channels upon extracellular stimuli, leading to ER calcium store depletion. This depletion triggers a conformational change in the stromal interaction molecule (STIM), a sensor located within the ER membrane. Activated STIM then interacts with ORAI proteins embedded in the plasma membrane, prompting the opening of CRAC channels and allowing extracellular calcium to flow into the cytoplasm.

CRAC-mediated calcium influx influences diverse cellular processes by activating various calcium-dependent signaling pathways. In the immune system, for instance, it is critical for the activation of T lymphocytes, facilitating the production of cytokines and other immune responses. Malfunctions or mutations in ORAI or STIM proteins can lead to immunodeficiency disorders and other pathological conditions.

Research into CRAC-mediated signaling continues to elucidate its roles in health and disease, highlighting its potential as a therapeutic target for immune-related and calcium signaling disorders. Overall, CRAC-mediated pathways represent a vital component of cellular calcium regulation and signal transduction.